WO2009085245A1 - Écran de projection frontale, son procédé de construction et système de projection frontale le comprenant - Google Patents

Écran de projection frontale, son procédé de construction et système de projection frontale le comprenant Download PDF

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Publication number
WO2009085245A1
WO2009085245A1 PCT/US2008/013978 US2008013978W WO2009085245A1 WO 2009085245 A1 WO2009085245 A1 WO 2009085245A1 US 2008013978 W US2008013978 W US 2008013978W WO 2009085245 A1 WO2009085245 A1 WO 2009085245A1
Authority
WO
WIPO (PCT)
Prior art keywords
light
transmission layer
selective transmission
front projection
projected
Prior art date
Application number
PCT/US2008/013978
Other languages
English (en)
Inventor
Gang Chen
Original Assignee
Alcatel-Lucent Usa Inc.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Alcatel-Lucent Usa Inc. filed Critical Alcatel-Lucent Usa Inc.
Publication of WO2009085245A1 publication Critical patent/WO2009085245A1/fr

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Classifications

    • G—PHYSICS
    • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
    • G03B—APPARATUS OR ARRANGEMENTS FOR TAKING PHOTOGRAPHS OR FOR PROJECTING OR VIEWING THEM; APPARATUS OR ARRANGEMENTS EMPLOYING ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ACCESSORIES THEREFOR
    • G03B21/00—Projectors or projection-type viewers; Accessories therefor
    • G03B21/54—Accessories
    • G03B21/56—Projection screens
    • G03B21/60—Projection screens characterised by the nature of the surface
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/20—Filters
    • G02B5/28—Interference filters

Definitions

  • the present invention is directed, in general, to front projection systems and, more specifically, to improving contrast of laser projected images in front projection systems.
  • Front projection systems may be installed at fixed locations, for example, in homes or meeting rooms. Front projections systems may also include a portable front projector and front projection screen that can be moved between different meeting rooms or to other locations.
  • Cathode ray tube (CRT) and Digital Light Processing (DLP) based projectors are examples of the front projectors that are currently being used in front projection systems.
  • front projection screens reflect and scatter the images projected thereon back to the viewer.
  • front projections systems present many different optical and arrangement challenges not present in rear projection systems . Accordingly, what is needed in the art are improvements for front projection systems.
  • the present invention provides an apparatus, a method of fabricating a front projection screen and a front projection system.
  • the apparatus includes a front projection screen including an image surface and a selective transmission layer fixed to and covering the surface.
  • the surface is configured to diffusely reflect light incident thereon and the selective transmission layer is configured to allow projected light from a laser source to illuminate the surface and substantially block ambient light incident thereon.
  • the laser projected light has a wavelength within a designated bandwidth.
  • the present invention provides the method of constructing a front projection screen.
  • the method includes: (1) obtaining an image surface configured to diffusely reflect light incident thereon and (2) attaching a selective transmission layer to the surface, wherein the selective transmission layer is configured to allow projected light from a laser source to illuminate the surface and to substantially block ambient light incident thereon, the projected light having a wavelength within a designated bandwidth.
  • the present invention provides the front projection system.
  • the front projection system includes: (1) a laser projector configured to project red, blue and green laser light to represent images and (2) a front projection screen.
  • the screen has an image surface configured to diffusely reflect light incident thereon including the red, blue and green light projected from the laser projector and has a selective transmission layer coupled to the surface.
  • the selective transmission layer is configured to allow the projected red, blue and green light to illuminate the surface and to substantially block ambient light incident thereon.
  • FIGURE IA illustrates a system diagram of an embodiment of a front projection system including a front projection screen constructed according to the principles of the present invention
  • FIGURE IB illustrates a diagram of an embodiment of a selective transmission layer physically coupled to a surface according to the principles of the present invention
  • FIGURE 2 illustrates a graph representing the properties of an embodiment of a selective transmission layer used according to the principles of the present invention
  • FIGURE 3 illustrates a flow diagram of a method of constructing a front projection screen carried out according to the principles of the present invention.
  • FIGURE IA illustrated is a system diagram of an embodiment of a front projection system 100 located in a room represented by a ceiling, a floor and a wall.
  • the front projection system 100 is used to present images to viewers by reflecting projected images to the viewers.
  • the front projection system 100 includes a laser projector 110 and a front projection screen 120 constructed according to the principles of the present invention.
  • the front projection system 100 illustrates a fixed installation with the laser projector 110 mounted on the ceiling and the front projection screen 120, e.g., attached to the wall.
  • the laser projector 110 or the front projection screen 120 may be portable apparatuses instead of installed at a particular location.
  • the laser projector 120 may be a conventional laser projector configured to present colored images to viewers by projecting, e.g., red, blue and green light on a front projection screen.
  • the laser projector 120 includes three laser sources at different wavelengths.
  • the laser sources may include, e.g. , a first laser that projects red light, a second laser that projects blue light and a third laser that projects green light.
  • the light projected by each laser source has a narrow bandwidth (e.g. , less than one nanometer) and a known center wavelength (e.g., for red, blue or green light) .
  • the laser projector 110 may project red light at a wavelength of about 630 nm (approximately any number between 610 and 650) , blue light at a wavelength of or about 475 (approximately any number between 420 and 480) nm and green light at a wavelength of or about 510 (approximately any number between 510 and 540) nm. More information on the operation and configuration of front projection systems using a laser projector can be found in U.S. Patent Application Serial No. 11/713,155, filed on March 2, 2007, by Vladimir Aksyuk et al . , and U.S. Patent Application Serial No. 11/765,155 filed of June 19, 2007, by Roland Ryf .
  • the front projection screen 120 is constructed to reflect images that are projected thereon.
  • the front projection screen 120 may be a fixed or portable apparatus.
  • the front projection screen 120 can be a fixed apparatus that is attached to the wall as illustrated in FIGURE IA or be free-standing with a base for support.
  • the front projection screen 120 may also be retractable. In other words, the front projection screen 120 can be pulled-down for viewing and then rolled-up after viewing.
  • the front projection screen 120 may also be a portable apparatus that can be collapsed and transported between locations.
  • the front projection screen 120 includes a surface 122 and a selective transmission layer 126.
  • the surface 122 is a conventional surface used to diffusely reflect and/or scatter light incident thereon and can be a conventional diffusely reflecting surface used in front projection systems.
  • the surface 122 can be the wall, a coating applied to the wall or may be attached to the wall as illustrated in FIGURE IA.
  • the surface 122 may be a white surface. In other embodiments, the surface 122 may be a gray surface.
  • the selective transmission layer 126 is placed in front of the surface 122 and is configured to selectively allow projected light from the laser projector 120 to illuminate the surface 122. In particular, the selective transmission layer 126 is configured to prevent ambient light from illuminating the surface 122.
  • Ambient light may cause a high background to the images projected on a conventional front projection screen.
  • ambient light is light that is not projected unto the front projection screen from the laser projector 110. More specifically, ambient light has a large diversity of polarizations and a bandwidth that is much larger than the bandwidths of the laser sources. As a result, the contrast of the projected images may be reduced in a front projection system.
  • the selective transmission layer 126 therefore, is configured to reduce the amount of ambient light to reach the surface 122. As such, the light reflected by the surface 122 is essentially the projected light from the laser projector 110. Accordingly, the contrast of the projected light from the laser projector 120 that is reflected to a viewer is improved over that in systems without the selective transmission layer 126.
  • the selective transmission layer 126 can be physically coupled to the surface 122 through various conventional chemical or mechanical means.
  • the selective transmission layer 126 may be laminated on the front of the surface 122 or applied as a coating. Additionally, the selective transmission layer 126 may be coupled to the surface 122 using mechanical fixtures such as screws and/or a frame.
  • FIGURE IB illustrates one embodiment of coupling the selective transmission layer 126 to the surface 122 (not identified in FIGURE IB) using screws 128 and a frame 129.
  • the selective transmission layer 126 can be added to the surface 122 post-manufacturing by an end-user or may be coupled to the surface 122 during manufacturing. Of course, one skilled in the art will understand that other methods of placing the selective transmission layer 126 in front of the surface 122 can be used.
  • the selective transmission layer 126 is "tuned" with the laser projector 120 to selectively allow light from the laser projector 120 to pass therethrough to the surface 122.
  • the selective transmission layer 126 therefore, may perform as a passband filter for the projected light from the laser projector 120.
  • the selective transmission layer 126 therefore, is designed and manufactured to allow the laser projected light to pass through to the surface 122.
  • FIGURE 2 represents the properties of an embodiment of a selective transmission layer 126.
  • the selective transmission layer 126 may be an interference filter having three narrow passbands that encompass each of the wavelengths of the red, blue and green light projected by the laser projector 110.
  • the interference filter may have three passbands with a first one of the three passbands encompassing the 475 nm wavelength of the projected blue light, a second one encompassing the 510 nm wavelength of projected green light and a third one encompassing the 630 nm wavelength of projected red light.
  • Light having a wavelength that is not in one of the passbands will be reflected by the interference filter. Essentially all ambient light, which ranges in wavelengths between approximately 400 nanometers to 650 nanometers, outside of these passbands would therefore be reflected and not illuminate the surface 122.
  • Eyewear such as glasses or goggles, having a layer of the interference filter may be used by a viewer to further enhance the image projected from the laser projector 110.
  • the enhanced eyewear can shield ambient light from the viewer and reduce the reflection of the ambient light from the interference filter of the selective transmission layer 126.
  • the eyewear with the interference filter will allow the red, blue and green laser lights to reach the viewer's eyes and reduce ⁇ e.g., block) the reception of ambient light to the viewer.
  • the enhanced eyewear may include a selective transmission layer 126 as used with the front projection screen 120.
  • the enhanced eyewear may also include a polarizing layer as discussed below.
  • the interference filter and/or polarizing layer may be physically coupled to lens of the enhanced eyewear through a conventional means.
  • each of the passbands may have a small bandwidth, such as a full-width-at-half-maximum intensity bandwidth of three nanometers or less. Indeed, the bandwidth of each of the passbands can even be much larger and still remove a substantial portion of the background or ambient light.
  • the passbands could be 20 nanometers or less and still reduce the intensity of white background light by about 50% (reduction of 50%) .
  • the width of passbands may be determined by multiplying the desired percentage of reduction by 0.4. Thus, for a reduction of about 33.33%, passbands of 13.33 nanometers or less could be used. Additionally, passbands of 10 nanometers or less could be used to provide a reduction of about 10%.
  • the interference filter can be made flexible and can be integrated with the surface 122 or closely attached to the front of the surface 122.
  • the front of the front projection screens is the side of the projection screens that receives light projected from the laser projector 110.
  • FIGURE 2 illustrates properties of an exemplary passband filter that can be used as the selective transmission layer 126.
  • the selective transmission layer 126 may be a linearly polarizing filter.
  • a linear polarizer filter transmits one of two states of linearly polarized light.
  • a linear polarizing filter can be configured to allow light polarized in the known state to pass through the selective transmission layer 126 (i.e., transmits the projected laser light) and onto the surface 122.
  • the known state may be vertically or horizontally polarized, i.e., for all laser color sources. The ambient light is unpolarized and half of it, therefore, will not illuminate the surface 122.
  • the linear polarizing layer may be a thin film linear polarizer attached to the surface 122.
  • a linear polarizing layer therefore, can be used as the selective transmission layer 126 or as part of the selective transmission layer 126.
  • the selective transmission layer 126 may include multiple layers that include an interference filter and a linear polarizing filter.
  • a layer including the interference filter may be the first layer next to the front side of the surface 122.
  • a layer including the linear polarizing filter may be the first layer next to the front side of the surface 122.
  • the selective transmission layer 126 is manufactured to allow light at these selected wavelengths to pass through to the surface 122. Additionally, the selective transmission layer 126 is configured to attenuate ambient light from illuminating the surface 122. Thus, the selective transmission layer 126 is manufactured to prevent most of the light that is not projected from the laser projector 120 from passing through to the surface 122. Accordingly, the contrast of the images that are projected onto the surface and reflected from the surface 122 is increased.
  • FIGURE 2 illustrates a graph representing the properties of an embodiment of a selective transmission layer, such as from FIGURE IA, used according to the principles of the present invention.
  • the present invention recognizes a laser projector uses narrow bands of lasers as the light source for forming the projected images.
  • Employing a selective transmission layer on a front projection screen allows the transmission of projected laser light having the narrow bandwidths while also reducing the transmission of ambient light to illuminate the screen. The contrast of the projected image can therefore be enhanced.
  • Employing a selective transmission layer is not effective, however, with projectors that do not project light at narrow wavelengths, such as projectors using illumination sources such as broadband lamps and LEDs .
  • an interference filter for designated wavelengths also refers to an interference filter of designated frequencies since frequencies is defined as the number of times a wavelength passes a designated point.
  • the graph of FIGURE 2 represents an interference filter which has three narrow transmission bands that encompass the wavelengths of red, green and blue light projected from a laser projector. Along the x-axis are the wavelengths in nanometers. The y-axis represents the intensity of the interference filter at the different wavelengths. Each of the passbands encompassing the red, blue and green light has an intensity full-width-at-half- maximum of approximately three nanometers or less. Light having a wavelength outside of the transmission bands is attenuated and substantially prevented from illuminating the surface of a front projection screen.
  • FIGURE 3 illustrates a flow diagram of a method 300 of constructing a front projection screen carried out according to the principles of the present invention.
  • the front projection screen is constructed to improve contrast of projected images from a laser front projector.
  • the method 300 begins in a step 305 with the intent to construct the front projection screen.
  • the surface may be an existing surface or may be fabricated specifically for constructing a front projection screen according to the present invention.
  • the surface may be a conventional surface used for front projection screens and can be manufactured employing a typical process understood by one skilled in the art.
  • the surface may be a highly reflective, opaque material.
  • a selective transmission layer is fabricated in a step 315.
  • the selective transmission layer may be fabricated as a dielectric coating having the desired passbands associated with the red, blue and green light projected from a laser source.
  • Edmund Optics Inc. of Barrington, New Jersey, for example, may manufacture the selective transmission layer 126 as a coating having the passband properties illustrated in FIGURE 2.
  • a coating including a linear polarizing filter may be included with the passband filter to comprise the selective transmission layer. Information regarding Edmund Optics Inc. can be found on their website.
  • a selective transmission layer is physically coupled to the surface in a step 320.
  • the selective transmission layer may be physically coupled to the surface by laminating the selective transmission layer to the surface.
  • the selective transmission layer can be attached to the surface via a mechanical fixture.
  • a frame can be attached around the outer edges of the selective transmission layer to secure the layer against the surface.
  • the selective transmission layer may be a coating that is applied to the surface. The selective transmission layer can be applied during manufacturing of the front projection screen or may be added post-manufacturing.
  • the selective transmission layer is configured to allow projected light from a laser projector to illuminate the surface and to substantially attenuate ambient light from illuminating the surface. Since the wavelength of light projected by the laser projector is known and within narrow bandwidths, the selective transmission layer is designed and constructed to allow transmission of the projected light. The selective transmission layer, therefore, allows a front projection screen to back scatter specific wavelengths of light within three specified narrow wavelength ranges, i.e., ranges of the laser sources. With the selective transmission layer placed in front of the surface, the contrast of images projected onto the surface from the laser projector is increased since light outside of the designated narrow ranges is prevented (e.g. , reflected) from passing through to the surface .
  • a viewer can use eyewear having an interference filter that allows the red, blue and green laser lights projected by the laser projector to reach the viewer's eyes and reduce (e.g., block) the reception of ambient light to the viewer.
  • the enhanced eyewear may include a selective transmission layer as used with the front projection screen.
  • the selective transmission layer is designed and constructed to allow transmission of the projected light from each of the lasers.
  • the selective transmission layer allows transmission of multiple known wavelengths to illuminate the surface.
  • the selective transmission layer can be designed to allow transmission of designated wavelengths of laser light and laser projectors can then be chosen accordingly.
  • the known wavelengths or wavelength ranges of laser light correspond to red light, blue light and green light.
  • the selective transmission layer includes an interference filter that allows transmission of the projected red, blue and green light but reflects other light incident thereon.
  • the selective transmission layer may include a linear polarizing filter.
  • the linear polarizing filter may be in addition to the interference filter.

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  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Projection Apparatus (AREA)
  • Transforming Electric Information Into Light Information (AREA)

Abstract

L'invention porte sur un appareil, sur un procédé de fabrication d'un écran de projection frontale et sur un système de projection frontale. Dans un mode de réalisation, l'appareil comprend un écran de projection frontale comprenant une surface d'image et une couche de transmission sélective fixée sur la surface et recouvrant celle-ci. La surface est configurée pour réfléchir de manière diffuse la lumière incidente sur celle-ci et la couche de transmission sélective est configurée pour permettre à une lumière projetée à partir d'une source laser d'éclairer la surface et pour bloquer la lumière ambiante incidente sur celle-ci. La lumière laser projetée a une longueur d'onde qui se situe dans la largeur de bande désignée.
PCT/US2008/013978 2007-12-28 2008-12-23 Écran de projection frontale, son procédé de construction et système de projection frontale le comprenant WO2009085245A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US11/966,977 2007-12-28
US11/966,977 US20090168026A1 (en) 2007-12-28 2007-12-28 Front projection screen, a method of constructing the same and a front projection system including the same

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WO2009085245A1 true WO2009085245A1 (fr) 2009-07-09

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CN102939762A (zh) * 2010-06-16 2013-02-20 伊斯曼柯达公司 提供减少的散斑伪像的投影装置
WO2017117728A1 (fr) * 2016-01-05 2017-07-13 深圳市亿思达科技集团有限公司 Centre d'informations à base de laser

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US9423602B1 (en) 2009-12-31 2016-08-23 Gene Dolgoff Practical stereoscopic 3-D television display system
US9752761B2 (en) 2014-07-16 2017-09-05 Telebrands Corp. Landscape light
USD773707S1 (en) 2014-10-30 2016-12-06 Telebrands Corp. Landscape light
JP6500414B2 (ja) * 2014-12-05 2019-04-17 大日本印刷株式会社 表示システムおよび観察具
USD766483S1 (en) 2015-05-11 2016-09-13 Telebrands Corp. Light projector
USD824066S1 (en) 2015-05-11 2018-07-24 Telebrands Corp. Light projector
USD816890S1 (en) 2015-05-11 2018-05-01 Telebrands Corp. Light projector
USD766484S1 (en) 2015-05-11 2016-09-13 Telebrands Corp. Light projector
USD778478S1 (en) 2015-05-11 2017-02-07 Telebrands Corp. Light projector
US9562673B1 (en) 2015-12-03 2017-02-07 Telebrands Corp. Decorative lighting apparatus having an attenuation assembly
US9458994B1 (en) 2015-12-03 2016-10-04 Telebrands Corp. Decorative lighting apparatus having two laser light sources and a switch
US9879847B2 (en) 2015-12-03 2018-01-30 Telebrands Corp. Decorative lighting apparatus having two laser light sources
US9546775B1 (en) * 2015-12-03 2017-01-17 Telebrands Corp. Decorative lighting apparatus having two laser light sources
USD798484S1 (en) 2016-09-29 2017-09-26 Telebrands Corp. Landscape light
USD797975S1 (en) 2016-09-29 2017-09-19 Telebrands Corp. Landscape light
EP3502674A1 (fr) * 2017-12-19 2019-06-26 Koninklijke Philips N.V. Essai de réseaux de diffraction de rayons x incurvés
GB2581366A (en) * 2019-02-14 2020-08-19 Constantino Mattthew Light blocking transparent display device
WO2023210779A1 (fr) * 2022-04-27 2023-11-02 大日本印刷株式会社 Système de projection et dispositif d'aide à l'observation

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CN102939762B (zh) * 2010-06-16 2015-09-02 伊斯曼柯达公司 提供减少的散斑伪像的投影装置
WO2017117728A1 (fr) * 2016-01-05 2017-07-13 深圳市亿思达科技集团有限公司 Centre d'informations à base de laser

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